A proof-of-concept study of ultrasound-guided continuous parasacral ischial plane block for postoperative pain control in patients undergoing total knee arthroplasty.

BACKGROUND: Continuous peripheral nerve blocks are widely used for anesthesia and postoperative analgesia in lower limb surgeries. The authors aimed to develop a novel continuous sacral plexus block procedure for analgesia during total knee arthroplasty. METHODS: The study comprised two stages. In Stage I, the authors built upon previous theories and technological innovations to develop a novel continuous sacral plexus block method, ultrasound-guided continuous parasacral ischial plane block (UGCPIPB) and subsequently conducted a proof-of-concept study to assess its effectiveness and feasibility. Stage II involved a historical control study to compare clinical outcomes between patients undergoing this new procedure and those receiving the conventional procedure. RESULTS: The study observed a 90% success rate in catheter placement. On postoperative day (POD) 1, POD2, and POD3, the median visual analog scale (VAS) scores were 3 (range, 1.5-3.5), 2.5 (1.6-3.2), and 2.7 (1.3-3.4), respectively. Furthermore, 96.3% of the catheters remained in place until POD3, as confirmed by ultrasound. The study revealed a significant increase in skin temperature and peak systolic velocity of the anterior tibial artery on the blocked side compared with those on the non-blocked side. Complications included catheter clogging in one patient and leakage at the insertion site in two patients. In Stage II, the novel technique was found to be more successful than conventional techniques, with a lower catheter displacement rate than the conventional procedure for continuous sciatic nerve block. CONCLUSION: UGCPIPB proved to be an effective procedure and safe for analgesia in total knee arthroplasty. CHINESE CLINICAL TRIAL REGISTRY NUMBER: ChiCTR2300068902.

Combined Pubic Arch and Ischial Bone Resection for Metachronous and Frequent Local Recurrences of Rectal Cancer.

BACKGROUND/AIM: Complete surgical resection with negative margins remains the cornerstone for curative treatment of rectal cancer; however, local recurrence can pose a significant challenge. Herein, we aimed to introduce a novel surgical technique for combined resection of the pubic arch and ischial bone in the context of treating recurrent rectal cancer. CASE REPORT: We present a case of a patient with a fourth local recurrence of rectal cancer, with no evidence of distant metastasis. The tumor directly invaded the posterior wall of the pubic arch. To achieve complete tumor resection, an osteotomy was performed using a thread wire saw at the bilateral pubic rami and ischial bones. Intraoperative frozen section analysis (rapid tissue examination) was conducted on tissue samples from the lateral margins of the planned osteotomy line. Samples were negative for adenocarcinoma (cancerous cells). The combined resection of the pubic arch and ischial bone was successfully performed with negative margins for adenocarcinoma, as confirmed by frozen section analysis. CONCLUSION: Mastery of the surgical technique for combined resection of the pubic arch and ischial bone may be clinically significant for achieving complete resection in cases of multiple resections for locally recurrent rectal cancer.

Stability of ischial pressure with 3D thermoplastic elastomer cushion and the characteristics of four types of cushions in pressure redistribution.

Wheelchair cushions are recommended to be used with wheelchair and can protect the buttocks from pain and injury by relieving interface pressure for wheelchair users. However, further investigations are required for proper use in response to the development of new types of wheelchair cushions. The objective of this study was to evaluate physical characteristics of wheelchair cushions by comparing pressure redistributing effects of four types of cushions. The participants were 16 healthy adults who consented to participate in this study. A pressure mapping system (CONFORMat, Nitta Corp.) was used for the measurements. Pressure at ischium was measured immediately after the stabilization of the sitting posture and 10 minutes after. The pressure at ischium significantly decreased with any wheelchair cushions (P < 0.01). A significant negative correlation between body mass index and pressure at ischium was observed without a wheelchair cushion (r = - 0.70), however, the correlation disappeared upon use of a wheelchair cushion. The pressure at ischium increased over time with cushions of urethane, air, and urethane-air hybrid while that with the 3D thermoplastic elastomer cushion did not, and the change in the pressure was statistically less than that in other cushions (P < 0.01). Use of wheelchair cushions was effective in redistribution of the pressure at ischium, and the overtime change in the pressure depends on the type of used cushions.

Adults Ischium Age Estimation Based on Deep Learning and 3D CT Reconstruction.

OBJECTIVES: To develop a deep learning model for automated age estimation based on 3D CT reconstructed images of Han population in western China, and evaluate its feasibility and reliability. METHODS: The retrospective pelvic CT imaging data of 1 200 samples (600 males and 600 females) aged 20.0 to 80.0 years in western China were collected and reconstructed into 3D virtual bone models. The images of the ischial tuberosity feature region were extracted to create sex-specific and left/right site-specific sample libraries. Using the ResNet34 model, 500 samples of different sexes were randomly selected as training and verification set, the remaining samples were used as testing set. Initialization and transfer learning were used to train images that distinguish sex and left/right site. Mean absolute error (MAE) and root mean square error (RMSE) were used as primary indicators to evaluate the model. RESULTS: Prediction results varied between sexes, with bilateral models outperformed left/right unilateral ones, and transfer learning models showed superior performance over initial models. In the prediction results of bilateral transfer learning models, the male MAE was 7.74 years and RMSE was 9.73 years, the female MAE was 6.27 years and RMSE was 7.82 years, and the mixed sexes MAE was 6.64 years and RMSE was 8.43 years. CONCLUSIONS: The skeletal age estimation model, utilizing ischial tuberosity images of Han population in western China and employing the ResNet34 combined with transfer learning, can effectively estimate adult ischium age.

Transiliac-Shortening Osteotomy to Treat Ischial Pressure Injury due to Fixed Pelvic Obliquity: A Case Report.

CASE: A 17-year-old adolescent boy with Gross Motor Function Classification System 5 cerebral palsy and neuromuscular scoliosis underwent posterior spinal fusion and segmental spinal instrumentation from T3 to the pelvis. He developed a right ischial pressure injury a few months postoperatively, which persisted despite nonoperative measures. He subsequently underwent an ipsilateral transiliac-shortening osteotomy 16 months after spinal surgery to treat his residual pelvic obliquity and the ischial pressure injury, which healed completely. At the 1-year follow-up visit, there were no further signs of pressure injury. CONCLUSION: This case report describes transiliac-shortening osteotomy as a viable treatment option for non-healing ischial pressure injuries secondary to fixed pelvic obliquity.

Anatomical Proximity Between Sciatic Nerve and Ischial Spine and its Relationship to the Development of Deep Gluteal Pain Syndrome.

OBJECTIVE: Deep gluteal syndrome (DGS) is a medical diagnosis in which the pathoanatomy of the subgluteal space contributes to pain. The growing recognition that gluteal neuropathies can be associated with the presence of a bone-neural conflict with irritation or compression may allow us to shed some light on this pathology. This study aims to determine whether the location of the sciatic nerve (SN) in relation to the ischial spine (IS) contributes to the development of DGS. METHODS: The SN - IS relationship was analyzed based on magnetic resonance imaging (MRI) in 15 surgical patients (SPs), who underwent piriformis release, and in 30 control patients who underwent MRI of the pelvis for reasons unrelated to sciatica. The SN exit from the greater sciatic foramen was classified as either zone A (medial to the IS); zone B (on the IS); or zone C (lateral to the IS). RESULTS: The SN was significantly closer to the IS in SPs than in MRI controls (P = 0.014). When analyzing patients of similar age, SNs in SPs were significantly closer (P = 0.0061) to the IS, and located in zone B significantly more (P = 0.0216) as compared to MRI controls. Patients who underwent surgery for piriformis release showed a significant decrease in pain postoperatively (P < 0.0001). CONCLUSIONS: The results from this study suggest that the relationship between the IS and SN may play a role in the development of DGS. This may also help establish which patients would benefit more from surgical intervention.

Surgical Correction of Ischiopagus Tripus Conjoined Twins with Fused Pelvis: Enhancing Quality of Life through Orthopedic Intervention.

BACKGROUND The rarity of ischiopagus tripus conjoined twins complicates the surgical separation, owing to the lack of cases and high complexity. We aim to report our experience in performing orthopedic correction for ischiopagus tripus twins. CASE REPORT A pair of 3-year-old conjoined boys presented with a fused body at the pelvis region and only 1 umbilicus. There were 2 legs separated by shared genitalia and an anus at the midline, and 1 fused leg, which could be felt and moved by both of the patients. The twins also shared internal organs of the bladder, intestine, and rectum, as visualized through angiography computerized tomography scan. After several team discussions with the institutional review board, the hospital ethics committee, and both parents, it was agreed to perform disarticulation of the fused third limb, followed by correction of the trunk alignment by pelvic closed wedge osteotomy and internal fixation. We successfully reconstructed the pelvis using locking plates and additional 3.5-mm cortical screws and 1.2-mm stainless steel wire. CONCLUSIONS This report describes the presentation and surgical management of a case of ischiopagus tripus conjoined twins. It highlights the challenges involved in surgery and the importance of investigating these infants for other congenital abnormalities. Although surgical approaches for different sets of twins should be individually tailored, interventions aimed to provide optimal outcomes should consider ethical issues and parental/patient expectations. Even in situations in which the twins are inseparable, there is still room for surgical correction to be performed.

Sonographic Appearance of the Ischiocondylar Origin of the Adductor Magnus.

The adductor magnus ischiocondylar origin (AM-IO) tendon has often been described as a third proximal hamstring tendon due to its common origin on the ischial tuberosity as well as similar function. Prior studies have described the magnetic resonance imaging characteristics of the AM-IO; however, its appearance on ultrasound has not been well-detailed. The purpose of our study is to describe the sonographic appearance of the AM-IO and provide a structured scanning protocol for complete evaluation of the tendon.

Anatomical study of the modified direct posterior gluteal splitting approach for acetabular fractures.

BACKGROUND: In this study, we investigated the area that can be addressed with an approach in which the skin incision is made directly above the dorsal column with Thiel cadaveric specimens. METHODS: Six Thiel cadaveric specimens were prepared. A skin incision was made directly above the dorsal column. The accessible proximal end from the proximal part of the greater sciatic notch to the gluteal ridge and the accessible distal end of the ischium were marked with a flat chisel. A molded 8-hole reconstruction plate was placed from the base of the ischium toward the gluteal ridge and fixed with 3 screws proximally and 2 screws distally. The length of the skin incision and the distance from each reference point on the bone to the reachable markings were assessed after the muscles were removed. RESULTS: Mean skin incision length was 9.3 ± 0.7 (range, 8.0-10.0) cm. In 3 of 6 cases, proximal screws were inserted through different spaces between muscle fibers. In all cases, we were able to reach at least the greater sciatic notch, the gluteal ridge at the level of superior border of the acetabulum, and the base of the ischial tuberosity. In all cases, an 8-hole plate could be placed from the gluteal ridge to the base of the ischium. There were no superior gluteal artery or sciatic nerve injuries in any of the cases. CONCLUSION: We anatomically investigated the area that can be addressed with an approach in which the skin incision was made directly above the dorsal column. In all cases, we were able to access the areas needed to reduce the fracture and place the plates necessary to stabilize the fracture through a 9.3 ± 0.7 cm skin incision. This approach can be a useful minimally invasive posterior approach for acetabular fractures.

Ischiorectal Fossa Tumors: 30-year Single-Institution Experience.

BACKGROUND: Primary tumors of the ischiorectal fossa are rare and comprise a wide array of pathologies with varying malignant potential. Because of the low prevalence, there is a paucity of data in the literature. This article presents a case series on the management of ischiorectal fossa tumors. OBJECTIVE: To present experience from 30 years of managing ischiorectal fossa tumors. DESIGN: Retrospective single-center analysis. SETTINGS: A quaternary referral academic health care center. PATIENTS: All patients treated for ischiorectal fossa tumors were included in the study. INTERVENTIONS: All patients underwent surgical management of their disease. MAIN OUTCOME MEASURES: Disease recurrence and overall survival. RESULTS: A total of 34 patients (53% women) were identified with a median follow-up of 23 months. Twenty-one patients (62%) were diagnosed with benign and 13 (38%) with malignant tumors. All underwent surgical resection. The median tumor size was 8.4 cm. R0 resection was obtained in 28 patients. Twelve patients (35%) developed recurrence (9 after R0 resection) after a median time of 6.5 months. There were no surgical-related mortalities. LIMITATIONS: Limitations to the study include its retrospective nature, single-center experience, and small patient sample size. CONCLUSIONS: Ischiorectal fossa tumors are primarily benign; however, they are associated with high recurrence rates even in the setting of an R0 resection. Treatment should be approached in a multidisciplinary manner, preferably in centers with experience treating these tumors. Close posttreatment surveillance is imperative. See Video Abstract . TUMORES DE LA FOSA ISQUIORRECTAL EXPERIENCIA DE AOS EN UNA SOLA INSTITUCIN: ANTECEDENTES:Los tumores primarios de la fosa isquiorrectal son raros y comprenden una amplia gama de patologías con potencial maligno variable. Debido a la baja prevalencia, hay escasez de datos en la literatura. Este artículo presenta una serie de casos sobre el tratamiento de los tumores de la fosa isquiorrectal.OBJETIVO:Presentar una experiencia de 30 años en el manejo de tumores de la fosa isquiorrectal.DISEÑO:Análisis retrospectivo de un solo centro.AJUSTES:Un centro de atención médica académico de referencia cuaternaria.PACIENTES:Todos los pacientes tratados por tumores de la fosa isquiorrectal.INTERVENCIONES:Todos los pacientes se sometieron a tratamiento quirúrgico de su enfermedad.PRINCIPALES MEDIDAS DE RESULTADO:Recurrencia de la enfermedad y supervivencia general.RESULTADOS:Se identificaron un total de 34 pacientes (53% mujeres) con una mediana de seguimiento de 23 meses. Veintiún pacientes (62%) fueron diagnosticados con tumores benignos y 13 (38%) con tumores malignos. Todos fueron sometidos a resección quirúrgica. El tamaño medio del tumor fue de 8,4 cm. La resección R0 se obtuvo en 28 pacientes. Doce (35%) desarrollaron recurrencia (nueve después de la resección R0) con una mediana de tiempo de 6,5 meses. No hubo mortalidades relacionadas con la cirugía.LIMITACIONES:Las limitaciones del estudio incluyen su naturaleza retrospectiva, experiencia en un solo centro y tamaño pequeño de la muestra de pacientes.CONCLUSIONES:Los tumores de la fosa isquiorrectal son principalmente benignos, sin embargo, se asocian con altas tasas de recurrencia incluso en el contexto de una resección R0. El tratamiento debe abordarse de forma multidisciplinaria y preferentemente en centros con experiencia en el tratamiento de estos tumores. Vigilancia cercana posterior al tratamiento es imperativa. (Traducción-Dr. Aurian Garcia Gonzalez).

Ischiofemoral impingement syndrome: A five-case series report.

Gluteal pain is a frequent cause of medical attention in the daily clinical practice. It can be caused by multiple pathologies, being ischiofemoral impingement syndrome among those included in its differential diagnosis. Encompassed within the deep gluteal syndromes, this entity occurs as a consequence of the entrapment of the neuromuscular structures between the lesser femoral trochanter and the ischial tuberosity, causing pain in the root of the lower limb, with irradiation towards the thigh or the gluteal region and poor tolerance to deambulation and sedestation. The magnetic resonance imaging of the hip is fundamental for its diagnosis, and its management consists on medical treatment at onset. Despite not being a frequent diagnosis in the clinical practice in Rheumatology, keeping it in mind helps improving its prognosis by establishing an early and adequate treatment.

Management of deep sacral and ischial pressure injuries with free-style local perforator flaps: A D+P+DPD model.

BACKGROUND: Previous reports on the treatment of sacral and ischial pressure injuries have not provided clear algorithms for surgical therapies. The objective of this study was to establish a reconstruction algorithm to guide the selection of an ideal free-style perforator flap that can be tailored to the defect in question. METHODS: We used 23 perforator flaps to reconstruct 14 sacral and 8 ischial defects in 22 patients over 5 years. A reconstruction algorithm system was developed based on the anatomical features of the perforator vessels (diameter, D; pulsatility [++∼+++], P) and their position in the skin island (DPD) (ie, D+P+DPD). A perforator-based propeller flap was applied as the first-line choice; if this plan was not feasible, we applied an altered V-Y advancement model or another second-choice technique. RESULTS: All flaps survived, and only 1 patient experienced partial wound dehiscence, which healed by secondary intention. After an average follow-up period of 11.2 months, no patient experienced recurrence or infection. CONCLUSIONS: Free-style perforator flap selection is determined by pressure injury and the desired advantage of a specific approach. The use of free-style perforator-based propeller flaps allows a surgeon to transfer healthy tissue into the defect, shifts the suture line away from the bony prominence, and preserves additional future donor sites. In cases where unexpected variations are encountered, the V-Y advancement model or another technique can be used. The simplified surgical algorithm (D+P+DPD) can provide versatility and reliability, achieve a durable, natural esthetic outcome, and minimize injuries to future donor sites.

van Neck-Odelberg disease: a common but poorly known and often misdiagnosed condition.

van Neck-Odelberg disease, a condition involving the ischiopubic synchondrosis in children, is a commonly encountered but poorly known ailment, which is now considered a normal variant. Symptoms can include pain, discomfort, and fever, leading to van Neck-Odelberg disease often being discovered in the context of patients presenting with non-specific clinical manifestations. In this essay, we describe what is currently known about van Neck-Odelberg disease and illustrate the condition using images acquired from multiple patients, with some using multiple imaging techniques from the same patients. Awareness of van Neck-Odelberg disease is essential for radiologists who are involved in the treatment of children, as well as for paediatricians, to prevent misdiagnosis and unnecessary invasive procedures for what is a benign and self-resolving condition.

Sagittal Pelvic Tilt Directly Influences the Ischiofemoral Space: A Cadaveric Study.

BACKGROUND: Ischiofemoral impingement (IFI) is understood to be a pain generator in the deep gluteal space. Femoral position is known to influence the ischiofemoral space (IFS), but there has been no study examining the effect of sagittal pelvic tilt on the IFS. The purpose of this study was to determine whether changes in pelvic tilt in the sagittal plane lead to changes in the dimensions of the IFS. MATERIALS AND METHODS: Five fresh frozen cadavers (10 hips) were used for this anatomic study. The specimens were skeletonized and placed in the prone position with the pelvis fixed to a custom-built hinged table. A digital inclinometer was used to tilt the pelvis -10°, 0°, and 10° simulating posterior, neutral, and anterior pelvic tilt, respectively. Digital calipers were used to measure the dimensions of the IFS in all three positions of sagittal pelvic tilt. RESULTS: Changes in pelvic tilt resulted in significant changes in the dimensions of the IFS. Mean IFS dimensions measured 29.3±9.7 mm, 37.2±9.0 mm, and 24.3±9.2 mm in the neutral, anterior, and posterior pelvic tilt positions, respectively (P<.0001). CONCLUSION: Changes in sagittal pelvic tilt influence the dimensions of the IFS, with posterior pelvic tilt noted to significantly decrease the IFS when compared with neutral and anterior pelvic tilt. These findings suggest that further evaluation of sagittal spinopelvic balance in the etiology of symptomatic IFI may be warranted. [Orthopedics. 2024;47(3):167-171.].

Editorial Commentary: Diagnosis of Hip Acetabular Retroversion Requires 3-Dimensional Imaging.

Diagnosis of global hip acetabular retroversion requires 3-dimensional imaging. Using anteroposterior pelvis radiographs, the crossover sign has been associated with retroversion. Recent research reports that the ischial spine sign and posterior wall sign also should be considered, yet even taking into account all 3 signs, the false-positive rate for retroversion is reported as greater than 35%. In truth, an anteroposterior radiograph is not sufficient for determination of acetabular retroversion. Retroversion is a 3-dimensional condition, and magnetic resonance imaging or computed tomography-based measurements are required. Thus, before we can determine the efficacy of hip arthroscopy versus periacetabular osteotomy for patients with hip impingement secondary to acetabular retroversion, we need to precisely measure to confirm our diagnosis.

Making the cut: a technical note and literature review of Bernese periacetabular osteotomy techniques with special attention to ischial osteotomy initiation and completion with an inside to anterior curved osteotomy.

Periacetabular osteotomy includes a fluoroscopy-guided ischial cut without direct visualization. Previously described techniques include a mediolateral ischial cortex cut, which is associated with the risk of injuring nearby nerves. Another drawback of that technique is the difficulty connecting an ischial cortex cut with a retroacetabular cut due to orthogonal nature of the osteotomy. In general, an additional cut from medial to lateral is required. The present study aimed to describe a technique that eliminates those problems due to use of only a central cut of the ischium and the curved nature of the osteotomy.

Determination of a Safe Zone for Ischial Screw Placement in Total Hip Arthroplasty.

BACKGROUND: Implantation of acetabular components with supplemental screw fixation is commonly performed to improve osteointegration and long-term stability in total hip arthroplasty (THA). Placement of ischial screws improves stability in biomechanical studies, but can be technically challenging. The study aimed to provide a safe zone for ischial screw placement with reference to easily identifiable intra-operative landmarks. METHODS: A retrospective review of patients was performed and 27 preoperative pelvis computed tomography scans were collected. After converting these images to 3-dimensional reconstructions of the pelvis, a safe zone for ischial screw placement was established with reference to the anterior superior iliac spine (ASIS) and the acetabular center and rim. RESULTS: The safe zone of an ischial screw in the en face sagittal plane was a median of 17 degrees (interquartile range [IQR]: 11,23) anterior to 13 degrees (IQR: 10,18) posterior to the reference line from the ASIS through the center of the acetabulum. The safe zone in the coronal plane was 34 degrees (IQR: 18,68) medial to 13 degrees (IQR: 8,19) lateral from a start point 1 centimeter medial to the inferior acetabular rim with a screw length of 25 millimeters. An ischial screw optimized for length directed down the center of the ischium was qualitatively demonstrated to have a start point unobtainable intraoperatively, originating within the cotyloid fossa. CONCLUSION: The ASIS, center of the acetabulum, and acetabular rim provide identifiable intraoperative landmarks for guiding ischial screw placement in hip arthroplasty.